def A(m, n):
    if m == 0:
        return n + 1
    if m > 0 and n == 0:
        return A(m - 1, 1)
    if m > 0 and n > 0:
        return A(m - 1, A(m, n - 1))
a = int(input())
b = int(input())
print(A(a, b))